Topical NAC Plus Doxycycline Shows Benefit in Moderate Acne
Key Takeaways
- Topical 5% N-acetylcysteine plus doxycycline outperformed 5% benzoyl peroxide plus doxycycline in a 40-patient RCT.
- Improvements were reported across lesion count, acne severity, IGA, and quality-of-life scores.
- Tolerability appeared favorable, with mild scaling reported in 1 NAC-treated patient.
Topical N-acetylcysteine (NAC) plus doxycycline was associated with greater improvement than benzoyl peroxide (BPO) plus doxycycline in patients with moderate acne vulgaris, according to findings from a double-blind randomized clinical trial.
The study included 40 patients assigned to receive either doxycycline 100 mg/day plus topical 5% NAC or doxycycline 100 mg/day plus topical 5% BPO for 3 months. Investigators assessed outcomes using total lesion count (TLC), Investigator Global Assessment (IGA), Global Acne Grading System (GAGS), and Cardiff Acne Disability Index (CADI).
Compared with the BPO group, the NAC group had greater reductions in CADI score (mean difference [MD], -3.60; 95% CI, -4.26 to -2.95; P < 0.001), GAGS score (MD, -9.76; 95% CI, -11.84 to -7.68; P < 0.001), and TLC (MD, -4.29; 95% CI, -6.38 to -2.19; P = 0.002). IGA scores also improved more in the NAC group (MD, -0.85; 95% CI, -1.12 to -0.58; P < 0.001).
One patient in the NAC group reported mild scaling. Cited limitations include the small sample size and 3-month follow-up.
“Topical NAC combined with doxycycline was significantly more effective than BPO-doxycycline in reducing acne severity and lesion count, with minimal adverse effects,” the authors wrote.
Source: Parvizi MM, et al. Dermatol Pract Concept. 2026;16(2):6215. Doi:10.5826/dpc.1602a6215